Figure 6.

In vivo biodistribution and MR imaging of GR@MMSNs-P. (a) In vivo fluorescence images of the mice bearing the 4T1 tumor after intravenous administration of free Cy5-siRNA and Cy5-GR@MMSNs-P at different time points and (b) the corresponding mean fluorescence intensity (MFI) values. (c) Ex vivo fluorescence images of major organs and tumor tissue harvested at 24 h postinjection. He: heart; Li: liver; Sp: spleen; Lu: lung; Ki: kidney; Tu: tumor. (d) Corresponding MFI values of ex vivo tissues at 24 h postinjection. (e) In vivo T₁-weighted MR images of the mice bearing the 4T1 tumor before and after intravenous injection of GR@MMSNs-P at 0, 1, 4, and 6 h.